Try and play to your strengths rather than thinking on the weakness of the opposite teams. Secondly, the top order has to stick atleast till 2/3rd or 3/4th of the game. Initially play off the ball understand the pitch and then can start scoring.

I've spent a lifetime of captaincy in various levels, but to focus on your circumstances, where there are under 16s and over 40s in the same side, its important they bond as a unit. Make sure each player knows what is expected of them in terms of contribution to the team.

Also, don't underestimate the social barriers with your players [when wide age variances prevail] - our 4th team go for a mid and end of season curry together where the kids and old 'uns get to socialise [to a degree]. If all your players can get along off the pitch, they will back each other up on it.